In recent years, mobile electronic equipment such as a mobile-phone, a game machine and the like has spread, and the capacity of the secondary battery which is built-in for those apparatuses has become larger and larger. In addition, along with the development of wireless technology, application of RFID (Radio Frequency Identification) which transmits & receives signals by small electric power has been expanding. In particular, with regard to an active RFID including a power supply, it is possible to carry out also a communication of few-hundreds meters or more. Consequently, expectation has been heightened for the application to the healthcare of cows, horses or the like in a ranch, for the application to safety management at the time of children's going to school and coming back from school, and the like.
On the other hand, for the improvement of maintenance of global environment, there have been actively carried out research and development of a battery and a power generator which have little environmental loads as much as possible. Within those matters, there has been reviewed a matter in which energy, which was consumed unconsciously and also fruitlessly in the past, is converted to electric energy and is charged in a secondary battery, wherein this electric energy is utilized as a power supply for electronic equipment or the like. As one example of such a power generator, it becomes a situation in which there has been devised a constitution of a vibration generator which converts vibration energy applied from the outside into electric energy and charges the energy in a secondary battery.
In Patent Document 1, there is disclosed a vibration generator which is provided with a vibrator composed of magnets whose same magnetic poles are faced to each other, a pipe for housing the vibrator and coils wound on the outer circumference of the pipe.